Many homeowners find it desirable to improve the attractiveness and nighttime visibility around their homes by installing exterior lighting fixtures. Many of these are mounted directly to the outside surface of the house. Several prior art enclosures are available for accommodating exterior wall-mounted electrical fixtures. These commonly feature several separate configurations to accommodate various types of electrical devices, such as light fixtures, duplex receptacles, or switches.
Modern construction techniques typically increase the complexity of mounting exterior electrical fixtures. The exterior surface of a home may typically include irregular shaped surfaces, such as lapped siding, which does not present the desired flat surface for accommodating a typically box-shaped mounting block. For some exterior finishes, such as those with stucco finishes, the substrate beneath the stucco may consist of a sheet structure such as Celotex®, a foam board that does not have the structural integrity to accept fasteners.
To simplify the task of installing an electrical fixture on the exterior of a building, the present inventor has provided several siding boxes. U.S. Pat. No. 5,804,764 to Gretz (hereinafter the '764 patent), for example, provided a two-piece siding box and cover assembly that included an UL-listed (Underwriters Labs) electrical junction box for housing electrical connections. The box included a breakaway rear flange. For mounting on an unfinished exterior surface, the rear flange could be retained and mounted on the wall. The exterior finish, such as lapped siding, could then be laid overtop the flange. Alternatively, for mounting on a finished house, a hole could be cut in the lapped siding, the breakaway rear flange on the box removed, and the box mounted within the newly created hole to the substrate. Unfortunately, for those situations in which the substrate cannot accept fasteners, the mounting block of the '764 patent was not entirely acceptable, as it forced homeowners to locate the box over a stud.
To provide more utility for mounting electrical fixtures to the exterior of a building, U.S. Pat. Nos. 6,051,786 and 6,239,368 (hereinafter the '786 and '368 patents) to Gretz provided a two-piece siding box having a rear edge conforming to the profile of lapped siding to which it may be attached. This siding box enabled easy installation by simply laying the rear edge over the lapped siding and driving fasteners directly into the siding.
Although the '786 and '368 patents simplified the task of mounting electrical fixtures to an exterior surface having lapped siding, the numerous styles of lapped siding available made it necessary to provide several mounting blocks with various rear edge geometries to accommodate the various lapped siding styles. In addition, the mounting block was not universal in that it was not easily used on flat surfaces.
Another drawback with the mounting block of the '764, '786, and '368 patents was the fact that the mounting blocks and associated covers had straight edges, necessitating that the straight edge of the cover be carefully lined up with the edge of the lapped siding to create an attractive finished installation. For those installations in which a hole was cut in the siding to expose the substrate, it became imperative for the homeowner to mark and cut very accurately to insure that the installed box and cover were lined up correctly with the siding.
Therefore, as can be seen from the above discussion, prior art siding boxes suffer several disadvantages when used on surfaces having lapped siding or a weak underlying substrate, such as foam board. When the siding were removed for direct mounting to the substrate, it was difficult to cut an appropriate hole and align it exactly with the siding. When the siding was retained, it was imperative to obtain a mounting block with a rear edge with the proper geometry conforming to the geometry of the actual siding it was mounted against.